Annie Poulin

Comparison of Stochastic Optimization Algorithms in Hydrological Model Calibration

AbstractTen stochastic optimization methods—adaptive simulated annealing (ASA), covariance matrix adaptation evolution strategy (CMAES), cuckoo search (CS), dynamically dimensioned search (DDS), differential evolution (DE), genetic algorithm (GA), harmony search (HS), pattern search (PS), particle swarm optimization (PSO), and shuffled complex evolution–University of Arizona (SCE–UA)—were used to calibrate parameter sets for three hydrological models on 10 different basins. Optimization algorithm performance was compared for each of the available basin-model combinations. For each model-basin pair, 40 calibrations were run with the 10 algorithms. Results were tested for statistical significance using a multicomparison procedure based on Friedman and Kruskal-Wallis tests. A dispersion metric was used to evaluate the fitness landscape underlying the structure on each test case. The trials revealed that the dimensionality and general fitness landscape characteristics of the model calibration problem are impo...

Planning Unidirectional Flushing Operations as a Response to Drinking Water Distribution System Contamination

This paper addresses the issue of contaminated water evacuation as part of the response process in cases of intentional or accidental contamination of drinking water distribution systems (DWDSs). Following a previous study which addressed contaminant isolation, an original flushing procedure (FP) is introduced. Through a heuristic set of rules, the FP defines unidirectional flushing (UDF) strategies in a safe, structured, and efficient manner. In addition to the rather theoretical considerations related to hydraulics modeling, the FP also takes into account the operational issues of UDF implementation. Compared to other similar studies, the latter aspect establishes the main contribution of this paper. The FP has been applied to two real-world networks and application of the heuristic rules is demonstrated with the aid of a detailed example. General results suggest possible improvements to existing network configurations and to the design of projected networks to better support contamination response plan...

Can Precipitation and Temperature from Meteorological Reanalyses Be Used for Hydrological Modeling

AbstractThis paper investigates the potential of reanalyses as proxies of observed surface precipitation and temperature to force hydrological models. Three global atmospheric reanalyses (ERA-Interim, CFSR, and MERRA), one regional reanalysis (NARR), and one global meteorological forcing dataset obtained by bias-correcting ERA-Interim [Water and Global Change (WATCH) Forcing Data ERA-Interim (WFDEI)] were compared to one gridded observation database over the contiguous United States. Results showed that all temperature datasets were similar to the gridded observation over most of the United States. On the other hand, precipitation from all three global reanalyses was biased, especially in summer and winter in the southeastern United States. The regional reanalysis precipitation was closer to observations since it indirectly assimilates surface precipitation. The WFDEI dataset was generally less biased than the reanalysis datasets. All datasets were then used to force a global conceptual hydrological model...

Added Value of Alternative Information in Interpolated Precipitation Datasets for Hydrology

AbstractGridded climate datasets are produced in many parts of the world by applying various interpolation methods to weather observations, to which are sometimes added secondary information (in addition to geographic location) such as topography and radar or atmospheric model outputs. For a region of interest, the choice of a dataset for a given study can be a significant challenge given the lack of information on the similarities and differences that exist between datasets, or about the benefits that one dataset may present relative to another. This study aims to provide information on the spatial and temporal differences between gridded precipitation datasets and their implication for hydrological modeling. Three gridded datasets for the province of Quebec are considered: the Natural Resources Canada (NRCan) dataset, the Canadian Precipitation Analysis (CaPA) dataset, and the dataset from the Ministere du Developpement Durable, de l’Environnement et de la Lutte contre les Changements Climatiques du Que...

Use of four reanalysis datasets to assess the terrestrial branch of the water cycle over Quebec, Canada

AbstractReanalyses have the potential to provide meteorological information in areas where few or no traditional observation records are available. The terrestrial branch of the water cycle of CFSR, MERRA, ERA-Interim, and NARR is examined over Quebec, Canada, for the 1979–2008 time period. Precipitation, evaporation, runoff, and water balance are studied using observed precipitation and streamflows, according to three spatial scales: 1) the entire province of Quebec, 2) five regions derived from a climate classification, and 3) 11 river basins. The results reveal that MERRA provides a relatively closed water balance, while a significant residual was found for the other three reanalyses. MERRA and ERA-Interim seem to provide the most reliable precipitation over the province. On the other hand, precipitation from CFSR and NARR do not appear to be particularly reliable, especially over southern Quebec, as they almost systematically showed the highest and the lowest values, respectively. Moreover, the partit...

Comparative Study of Pressure Reduction Valve Controllers in Water Distribution Systems

Pressure control is effective to reduce water losses in water distribution systems. It can be achieved by installing pressure reduction valves controlled in real time. An experimental campaign was carried out to compare Proportional–Integral–Derivative (PID) controllers for these valves. The Proportional controller presents the best results closely followed by the Proportional-Integral.

Global model MOHYSE, a new tool to assess the effect of hydro-meteorological phenomena in the tropics

In this research the adaptation to tropical conditions of a Canadian global hydrological model (GHM) called MOHYSE was performed, and the efficiency of its hydrological response was evaluated. A hydrological modeling study over central watersheds of the Gulf of Mexico was performed and various indices were calculated to evaluate the GHM response. Additionally, the GHM was compared with a semi-distributed hydrological model (SDHM) to determine which of the models was closest to the hydrograph observed in the study area. The results indicate that both models adequately fit to tropical conditions; however the MOHYSE obtained better results in the statistical analysis compared to the SDHM, mainly with the Nash-Sutcliffe efficiency coefficient. Likewise, these results have direct application in the analysis of flood risk areas and could serve as an useful tool for policy makers.